Topological parameter design and reliability analysis of single-module 90KW resonant medium-voltage DC converter for offshore DC wind turbine

With the gradual increase of wind turbine offshore distance, the all-DC system scheme has become a research hotspot, and in the all-DC offshore wind power system, the DC boost converter is one of the core equipment. Among them, the LLC resonant topology with good gain properties and soft switching of both primary and secondary side devices and the high-frequency transformer has become the key components to determine the performance of the system. A new fixed resonant capacitor parameter calculation method is proposed, which can be classified as multi-objective optimization of the resonant structure so that the DC-DC converter not only has the gain characteristics under wide range input voltage, but also considerable efficiency. The stable long-term operation capability of the LLC DC-DC converter was evaluated.